Magnetic recording medium for thermally assisted recording

Abstract

A magnetic recording medium is capable of improving the efficiency of thermal energy supply to a magnetic recording layer. A magnetic recording medium for thermally assisted recording comprises at least a nonmagnetic substrate, a magnetic recording layer, and a reflectance change layer. The magnetic recording layer is positioned between the substrate and the reflectance change layer.

What is claimed is: 
     
         1 . A magnetic recording medium for thermally assisted recording, comprising at least a nonmagnetic substrate, a magnetic recording layer, and a reflectance change layer,
 wherein the magnetic recording layer is positioned between the substrate and the reflectance change layer.   
     
     
         2 . The magnetic recording medium for thermally assisted recording according to  claim 1 , wherein the reflectance change layer is formed from a material the reflectance of which can be changed reversibly. 
     
     
         3 . The magnetic recording medium for thermally assisted recording according to  claim 1 , wherein the reflectance change layer is formed from a material the reflectance of which can be changed by irradiation with control light. 
     
     
         4 . The magnetic recording medium for thermally assisted recording according to  claim 3 , wherein the reflectance change layer is formed from a phase transition material. 
     
     
         5 . The magnetic recording medium for thermally assisted recording according to  claim 3 , wherein the reflectance change layer is formed from a material including one or a plurality of elements selected from a group consisting of germanium (Ge), antimony (Sb), tellurium (Te), gallium (Ga) and selenium (Se). 
     
     
         6 . The magnetic recording medium for thermally assisted recording according to  claim 3 , wherein the reflectance change layer is formed from a metal-semiconductor phase transition material made of Ti 3 O 5 . 
     
     
         7 . The magnetic recording medium for thermally assisted recording according to  claim 1 , wherein the reflectance change layer has a low-reflectance region and a high-reflectance region, and the reflectance of the low-reflectance region is equal to or lower than the reflectance of the high-reflectance region. 
     
     
         8 . The magnetic recording medium for thermally assisted recording according to  claim 7 , wherein the magnetic recording medium for thermally assisted recording includes a recording track region and a servo region, and the low-reflectance region is formed in at least a portion of the recording track region. 
     
     
         9 . The magnetic recording medium for thermally assisted recording according to  claim 7 , wherein the magnetic recording medium for thermally assisted recording includes a recording track region and a servo region, and the low-reflectance region is formed in at least a portion of the servo region. 
     
     
         10 . An article of manufacture, comprising:
 a data recording layer; and   a recording assistance layer formed on the data recording layer;   wherein a reflectance of the recording assistance layer is changeable by a controlled light irradiation on the recording assistance layer.   
     
     
         11 . The article of manufacture of  claim 10 , wherein the recording assistance layer is configured to change a recording characteristic of the data recording layer based on the reflectance. 
     
     
         12 . The article of manufacture of  claim 10 , wherein the recording assistance layer includes a material of a first reflectance that is changeable by the controlled light irradiation into a second reflectance different from the first reflectance. 
     
     
         13 . The article of manufacture of  claim 12 , wherein a change by the controlled light irradiation is reversible. 
     
     
         14 . The article of manufacture of  claim 12 , wherein an area having the first reflectance is formed over a position of the data recording layer where data is to be recorded. 
     
     
         15 . The article of manufacture of  claim 14 , wherein the first reflectance is lower than the second reflectance. 
     
     
         16 . The article of manufacture of  claim 11 , wherein a magnetic anisotropic energy of the data recording layer is changeable by a recording light irradiation associated with recording on the data recording layer, based on the reflectance, to change the recording characteristic of the data recording layer. 
     
     
         17 . A method, comprising:
 forming a data recording layer;   forming a recording assistance layer on the data recording layer; and   changing a reflectance of the recording assistance layer by a controlled light irradiation on the recording assistance layer.   
     
     
         18 . The method of  claim 17 , further comprising:
 changing the reflectance of the recording assistance layer to be lower in a region corresponding to a position of the data recording layer where data is to be recorded than in an adjacent region.   
     
     
         19 . The method of  claim 17 , further comprising
 reversing a change in the reflectance of the recording assistance layer.   
     
     
         20 . The method of  claim 17 , further comprising:
 irradiating the region of the recording assistance layer corresponding to the position of the data recording layer where data is to be recorded with a recording light to change a recording characteristic of the data recording layer.